1. Field of the Invention
The present invention relates to a semiconductor device that amplifies and outputs an error (a difference) between two signals and a method for driving the semiconductor device. The present invention particularly relates to the semiconductor device having a function of stopping its operation (a standby function) and a method for driving the semiconductor device. Note that in this specification, a semiconductor device refers to any device that operates by utilizing semiconductor properties.
2. Description of the Related Art
The rise of environmental awareness requires the reduction in power consumption of a variety of semiconductor devices. For example, Patent Document 1 discloses a technique for reducing power consumption of a multiple frequency switching power supply having a pulse width modulation circuit (a power supply circuit controlled by a pulse width modulation (PWM) method). Specifically, the power supply changes the frequency of a clock signal supplied to the pulse width modulation circuit in accordance with whether the pulse width modulation circuit is in a normal operation mode or a waiting (standby) mode, thereby reducing power consumption.